I've had All the MPA chassis models, hybrid was the favorite and real versatile, the Matrix was stellar but heavy!
I've had All the Manners models, the Tcs was real good, but also hard to get balanced without being super heavy too. Favorite is the Nightstalker currently and if the LRH-NV wasn't so hollow sounding, I'd love it more than the Nightstalker.
I've had several KRG chassis and selling my Whiskey3. It's great too, but I sorta don't love the magwell and found with heavy L3i mags, it won't feed awesome, anything else is fine tho. The X-ray was good for the price tho.
I've only had 2 MDT standard chassis and while not a great showing for the lineup of theirs, was a nice solid chassis, but I don't love their grip. MPA for the win in my book and why I modify the grips for all my chassis that I can fit them on. I do have 1 of 2 the HNT26 I owned and it's great for folding and light weight, wish the forend was a bit stiffer, the Crbn stock tho is great for my dedicated thermal gun..wish the grip was a bit straighter tho.
XLR used to get bashed by me for the AR butt stock attachment looking like an AR ass end but after having 3 Mag 4.0 and 1 3.0, the thumb shelf is MONEY and a favorite accessory for a chassis. These have become a replacement for the MPAs for that and ease of clamping into my RRS tripod in the dark (seems to be easier to clamp for some reason is all). The rest of the lineup hasn't been tried by me tho. Their NV rail is too high for clipon use but I read a modification can be done for it to be lower for that use.
Foundation, I've had 1 MG2 and 2 Centurions and 1 Revelation. I LOVE the revelation and the others are good but my fat thumb pad doesn't fit great but got ballsy and ground out a swale for my hand to fit better and it's what I'm running now. If you run a vudoo with MTU, plan on the rig weighing 16-18 pounds with scope but it will balance easier than the TCS.
I have a Russo laminate stock now, sort of a copy of a manners stock, that for a convention stock is AMAZING. Wish I had another one.
Limited use with the greyboe stocks and the McMillan variants but I like trying new stuff and each has a reason for liking it or trying it and I used try to do a lot of competition and try to still, but 22s and Fclass / Long range stuff along with the annual prairie dog trip have me looking at lots of options and most of my dislikes are rather nit-picky.